Is she part Japanese Snowshoe by chance? She looks a lot like one in the face, eyes, and markings.

Siamese Mix.. she has two sibling and its kind of interesting to see who get more of the breed in them... one of them was pretty much pure white with some orange highlights and the other one was pretty much a pure looking siamese.. she was in the middle! lol

I do believe she would be categorized as a Lynx Point which is a mix of a pure siamese with a tabby.
My other cat is almost a Lynx Point but darker.